The invention relates to an apparatus for monitoring a wearer of breathing apparatus.
Breathing apparatus, such as self-contained breathing apparatus (SCBA), is frequently used by persons working in hazardous environments. Breathing apparatus typically comprises a cylinder of breathable gas mounted on a harness carried by the user, and a delivery device, such as a facemask having a lung-demand valve, that supplies the breathable gas to the user. A pressure gauge, such as a manual gauge or a digital gauge, is usually provided so that the wearer can monitor the amount of breathable gas remaining in the cylinder.
A mobile monitoring device such as a PASS (Personal Alert Safety System) or ADSU (Automatic Distress Signal Unit) is often used with breathing apparatus and in some cases is required by law. A PASS/ADSU comprises a motion sensor that monitors the motion of the wearer and an alarm, for example an audible or visual alarm, that is activated if a lack of motion is detected for a pre-determined period of time. A lack of motion may indicate that the wearer is injured or incapacitated and the alarm is used to alert rescue personnel to the location of the wearer.
It is important that the mobile monitoring device is turned on before the wearer enters the hazardous environment. This is typically done by pressing a combination of manual buttons or removing a tally key from the device. GB 2 496 402 discloses monitoring apparatus in which a mobile monitoring device is turned on when it has been detected that the gas supply has been turned on. Accordingly, the mobile monitoring device is automatically turned on when the wearer turns the gas supply on.
However, wearers of breathing apparatus are frequently required to remain outside of a hazardous environment in readiness for deployment into the environment. Although they are waiting to be deployed, the gas supply of their breathing apparatus is turned on so that they can immediately enter the hazardous environment when instructed. In such circumstances an activated PASS/ADSU will sound the alarm if a lack of motion is detected. Motionless wearers awaiting deployment can therefore be frequently disturbed by an alarm unnecessarily, and must manually turn off the alarm each time it is activated.
It is therefore desirable to provide an improved apparatus for monitoring a wearer of breathing apparatus.
According to an aspect of the invention there is provided a monitoring apparatus for monitoring a wearer of breathing apparatus comprising a source of breathable gas which in use is supplied to a delivery device via a fluid line, the monitoring apparatus comprising: a breathing detector arranged to determine if breathing using the breathing apparatus has commenced; and a mobile monitoring device arranged to be associated with the wearer and which can be activated to monitor the motion of the wearer; wherein the apparatus is arranged to activate the mobile monitoring device when it is determined that breathing has commenced. The delivery device may comprise a face mask and/or a lung demand valve.
The mobile monitoring device may be arranged to be attached to the wearer.
The breathing detector may be arranged to monitor a signal relating to a parameter of fluid in the fluid line. The breathing detector may be arranged to determine if breathing has commenced based on the signal.
The signal may comprise a pressure signal relating to the pressure of fluid in the fluid line. The monitoring apparatus may comprise a pressure sensor which is arranged to generate the pressure signal.
The breathing detector may determine that breathing has commenced when the pressure signal indicates that the pressure of fluid in the fluid line has fallen by at least a predetermined pressure. The breathing detector may determine that breathing has commenced when the pressure signal indicates that the pressure of fluid in the fluid line has fallen at a rate that is at least a predetermined rate.
The signal may comprise a flow rate signal relating to the flow rate of fluid in the fluid line. The monitoring apparatus may comprise a flow rate sensor which is arranged to generate the flow rate signal. The breathing detector may determine that breathing has commenced when the flow rate signal indicates that the flow rate of fluid in the fluid line is at least a predetermined flow rate.
The monitoring apparatus may further comprise a gas supply detector arranged to determine if breathable gas is being supplied to the delivery device.
The monitoring apparatus may be arranged to activate the mobile monitoring device when it is determined that both breathable gas is being supplied to the delivery device and breathing has commenced.
The monitoring apparatus may be arranged such that the breathing detector starts determining if breathing has commenced only once the gas supply detector has determined that breathable gas is being supplied to the delivery device.
The gas supply detector may be arranged to monitor a signal relating to a parameter of fluid in the fluid line. The gas supply detector may determine if breathable gas is being supplied based on the signal.
The signal may comprise a pressure signal relating to the pressure of fluid in the fluid line. The monitoring apparatus may comprise a pressure sensor which generates a pressure signal relating to the pressure of fluid in the fluid line.
The gas supply detector may determine that breathable gas is being supplied when the pressure signal indicates that the pressure of fluid in the fluid line is at least a predetermined pressure.
According to a further aspect of the invention there is provided breathing apparatus comprising: a source of breathable gas fluidically coupled to a delivery device via a fluid line, such that in use breathable gas can be supplied to the delivery device via the fluid line; and a monitoring apparatus in accordance with any statement herein. The delivery device may comprise a face mask and a lung demand valve. The source of breathable gas may comprise a cylinder of breathable gas.
According to a further aspect of the invention there is provided a method of activating a mobile monitoring device which is arranged to be associated with a wearer of breathing apparatus comprising a source of breathable gas which in use is supplied to a delivery device via a fluid line, the method comprising: determining if breathing using the breathing apparatus has commenced; and activating the mobile monitoring device to monitor the motion of the wearer when it is determined that breathing has commenced.
The mobile monitoring device may be arranged to be attached to the wearer.
The method may further comprise monitoring a signal relating to a parameter of fluid in the fluid line. Determining if breathing has commenced may be based on the signal.
The signal may comprise a pressure signal relating to the pressure of fluid in the fluid line. It may be determined that breathing has commenced when the pressure signal indicates that the pressure of fluid in the fluid line has fallen by at least a predetermined pressure. It may be determined that breathing has commenced when the pressure signal indicates that the pressure of fluid in the fluid line has fallen at a rate that is at least a predetermined rate.
The signal may comprise a flow rate signal relating to the flow rate of fluid in the fluid line. It may be determined that breathing has commenced when the flow rate signal indicates that the flow rate of fluid in the fluid line is at least a predetermined rate.
The method may further comprise determining if breathable gas is being supplied to the delivery device.
The mobile monitoring device may be activated when it is determined that both breathable gas is being supplied to the delivery device and breathing has commenced. Determining if breathing has commenced may only start once it has been determined that breathable gas is being supplied to the delivery device.
The method may further comprise monitoring a signal relating to a parameter of fluid in the fluid line. Determining if breathable gas is being supplied may be based on the signal.
The signal may comprise a pressure signal relating to the pressure of fluid in the fluid line. It may be determined that breathable gas is being supplied when the pressure signal indicates that the pressure of fluid in the fluid line is at least a predetermined pressure.
The invention may comprise any combination of the features and/or limitations referred to herein, except combinations of such features as are mutually exclusive.